The country music star was performing when a gunman opened fire on the open-air Route 91 Harvest Festival, killing 58 and injuring over 500 more. He began the late-night sketch comedy show by delivering a heartfelt speech, followed by an emotional performance of Tom Petty's "I Won't Back Down." The song choice was especially notable given that the legendary singer died the day after the shooting at age 66 after suffering cardiac arrest.

"So many people are hurting... Children, brothers, sisters, parents -- they're all part of our family," Aldean said before the performance. "We're gonna work through these tough times together, all the way."

The appearance came on the night of one of Aldean's cancelled shows, which the 40-year-old musician decided not to go forward with in light of the traumatic shooting.

"As a result of what happened in Las Vegas this week, we have decided to cancel this coming weekend's shows," Aldean said in a statement of his cancelled shows earlier this week. "I feel like out of respect for the victims, their families and our fans, it is the right thing to do. It has been an emotional time for everyone involved this week, so we plan to take some time to mourn the ones we have lost and be close with our family and friends."